Drinking flask



FIG. 1 is a front elevation view of a drinking flask showing my new design; the rear being a mirror image thereof;

FIG. 2 is a left side elevation view of the drinking flask of FIG. 1; the right side being a mirror image thereof;

FIG. 3 is a top view of the drinking flask of FIG. 1;

FIG. 4 is a bottom view of the drinking flask of FIG. 1; and,

FIG. 5 is a top perspective view of the drinking flask of FIG. 1. 

CLAIM The ornamental design for a drinking flask, as shown and described. 